package com.soujiayi.net;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Collections;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.util.DisplayMetrics;
import android.widget.ImageView;

import com.soujiayi.util.CommonUtils;
import com.soujiayi.util.FileCache;
import com.soujiayi.util.MemoryCache;

public class ImageLoader {

	private MemoryCache memoryCache = new MemoryCache();
	private FileCache fileCache;
	private Map<ImageView, String> imageViews = Collections
			.synchronizedMap(new WeakHashMap<ImageView, String>());
	private ExecutorService executorService;
	private boolean isSaveToSD = false;
	private float scalX;//屏宽
	private float scalY;//屏高

	public ImageLoader(Context context, boolean isSaveToSD, float with, float height, int threadNum) {
		DisplayMetrics dm = new DisplayMetrics();  
		dm = context.getResources().getDisplayMetrics();
		scalX = with*dm.density;
		scalY = height*dm.density;
		this.isSaveToSD = isSaveToSD;
		if (isSaveToSD) {
			fileCache = new FileCache(context);
		}
		executorService = Executors.newFixedThreadPool(threadNum);
	}

	final int stub_id = com.soujiayi.activity.R.drawable.pic_loading;

	public void DisplayImage(String url, ImageView imageView) {
		imageViews.put(imageView, url);
		Bitmap bitmap = memoryCache.get(url);
		if (bitmap != null)
			imageView.setImageBitmap(bitmap);
		else {
			queuePhoto(url, imageView);
			imageView.setImageResource(stub_id);
		}
	}

	private void queuePhoto(String url, ImageView imageView) {
		PhotoToLoad p = new PhotoToLoad(url, imageView);
		executorService.submit(new PhotosLoader(p));
	}

	private Bitmap getBitmap(String url) {
		if (this.isSaveToSD) {
			File f = fileCache.getFile(url);

			// ��sd��
			Bitmap b = decodeFile(f);
			if (b != null)
				return b;
		}

		// ������
		try {
			Bitmap bitmap = null;
			URL imageUrl = new URL(url);
			HttpURLConnection conn = (HttpURLConnection) imageUrl
					.openConnection();
			conn.setConnectTimeout(30000);
			conn.setReadTimeout(30000);
			conn.setInstanceFollowRedirects(true);
			InputStream is = conn.getInputStream();
			if (this.isSaveToSD) {
				File f = fileCache.getFile(url);
				OutputStream os = new FileOutputStream(f);
				CommonUtils.CopyStream(is, os);
				os.close();
				bitmap = decodeFile(f);
			}else{
				//bitmap = decode(is);
				bitmap = adaptive(BitmapFactory.decodeStream(is, null, null));
			}
			 
			return bitmap;
		} catch (Exception ex) {
			System.out.println(ex);
			return null;
		}
	}
	
    public Bitmap adaptive(Bitmap bitmap) {
        Matrix matrix = new Matrix();
        int width = bitmap.getWidth();// 获取资源位图的宽
        int height = bitmap.getHeight();// 获取资源位图的高
        float w = scalX / bitmap.getWidth();
        float h = scalY / bitmap.getHeight();
        matrix.postScale(w, h);// 获取缩放比例
                    // 根据缩放比例获取新的位图
        Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height,matrix, true);
        return newbmp;  
    }

	// ����ͼ�����������ڴ����
	private Bitmap decodeFile(File f) {
		Bitmap bitmap = null;
		try {
			// ����ͼ���С
			BitmapFactory.Options o = new BitmapFactory.Options();
			o.inJustDecodeBounds = true;
			BitmapFactory.decodeStream(new FileInputStream(f), null, o);

			// �ҵ���ȷ�Ŀ̶�ֵ����Ӧ����2���ݡ�
			final int REQUIRED_SIZE = 70;
			int width_tmp = o.outWidth, height_tmp = o.outHeight;
			int scale = 1;
			while (true) {
				if (width_tmp / 2 < REQUIRED_SIZE
						|| height_tmp / 2 < REQUIRED_SIZE)
					break;
				width_tmp /= 2;
				height_tmp /= 2;
				scale *= 2;
			}

			BitmapFactory.Options o2 = new BitmapFactory.Options();
			o2.inSampleSize = scale;
			bitmap = BitmapFactory.decodeStream(new FileInputStream(f), null,
					o2);
		} catch (FileNotFoundException e) {
		}
		return bitmap;
	}

	// �������
	private class PhotoToLoad {
		public String url;
		public ImageView imageView;

		public PhotoToLoad(String u, ImageView i) {
			url = u;
			imageView = i;
		}
	}

	class PhotosLoader implements Runnable {
		PhotoToLoad photoToLoad;

		PhotosLoader(PhotoToLoad photoToLoad) {
			this.photoToLoad = photoToLoad;
		}

		public void run() {
			if (imageViewReused(photoToLoad))
				return;
			Bitmap bmp = getBitmap(photoToLoad.url);
			memoryCache.put(photoToLoad.url, bmp);
			if (imageViewReused(photoToLoad))
				return;
			BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
			Activity a = (Activity) photoToLoad.imageView.getContext();
			a.runOnUiThread(bd);
		}
	}

	boolean imageViewReused(PhotoToLoad photoToLoad) {
		String tag = imageViews.get(photoToLoad.imageView);
		if (tag == null || !tag.equals(photoToLoad.url))
			return true;
		return false;
	}

	// ������ʾλͼ��UI�߳�
	class BitmapDisplayer implements Runnable {
		Bitmap bitmap;
		PhotoToLoad photoToLoad;

		public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
			bitmap = b;
			photoToLoad = p;
		}

		public void run() {
			if (imageViewReused(photoToLoad))
				return;
			if (bitmap != null)
				photoToLoad.imageView.setImageBitmap(bitmap);
			else
				photoToLoad.imageView.setImageResource(stub_id);
		}
	}

	public void clearCache() {
		memoryCache.clear();
		if(this.isSaveToSD){
			fileCache.clear();
		}
	}
	
	public void close(){
		executorService.shutdownNow();
	}

}